1. Field of the Invention
The present invention relates to a data processing apparatus using a ring bus, a method of controlling the same, and a storage medium storing a program.
2. Description of the Related Art
Conventionally, there exists a data processing method which executes data processing using a bus-type pipeline connection formed by arranging processing circuits in parallel. In this connection scheme, data input from an external memory or an external I/F to the input terminal is processed in the connection order and output from the output terminal to an external memory or the like. In this case, it is impossible to change the process order even if the user wants to.
For this purpose, Japanese Patent Laid-Open No. 01-023340 proposes a method of connecting data processing circuits using a ring bus. Japanese Patent Laid-Open No. 63-247858 proposes a technique of executing image filter processing in parallel. This technique sends data with an attached control code to the ring bus and controls data reception based on the control code so that a plurality of processors can receive the data that overlap in data transfer between the data processing circuits. Various kinds of methods have thus been proposed to change the order in the ring bus.
Conventionally, however, if a data process order that does not comply with the connection order is set in ring bus connection, the data flow in the communication path between process modules in the ring bus may have an overlapping section, and communication of one of the process modules may be forced to wait. In the overlapping section, since the amount of transmission data increases, the performance of the communication process is poor.